A comparative study on acute toxicity of methylarsonic acid, dimethylarsinic acid and trimethylarsine oxide in mice

The acute toxicity of methylarsonic acid, CH3AsO(OH)2 (MAA), dimethylarsininc acid, (CH3)2AsO(OH) (DMAA), and trimethylarsine oxide, (CH3)3AsO (TMAO), were examined in mice with oral administration. The LD50 values of MAA, DMAA and TMAO were 1.8, 1.2 and 10.6 g kg−1 respectively. The toxicity of MAA and DMAA was very much lower than that for inorganic arsenic compounds. It was shown that TMAO has a similar acute toxicity to arsenobetaine. On the other hand, when the mice were administered 14.4 g kg−1 of TMAO once only orally, a garlic‐like odor (trimethylarsine, (CH3)3As) was definitely detectable in the exhalation of the animals by the human olfactory sense within about a few minutes.